\documentclass{article}
\usepackage[x11names, rgb]{xcolor}
\usepackage[utf8]{inputenc}
\usepackage{tikz}
\usetikzlibrary{snakes,arrows,shapes}
\usepackage{amsmath}
%
%
\usepackage[active,tightpage]{preview}
\PreviewEnvironment{tikzpicture}
\setlength\PreviewBorder{0pt}%
\usetikzlibrary{automata}%

\begin{document}
\pagestyle{empty}
%
%
%

\enlargethispage{100cm}
% Start of code
% \begin{tikzpicture}[anchor=mid,>=latex',join=bevel,]
\begin{tikzpicture}[>=latex',join=bevel,]
  \pgfsetlinewidth{1bp}
\Huge%
\pgfsetcolor{black}
  % Edge: q1 -> q3
  \draw [->] (70bp,177bp) .. controls (76bp,164bp) and (83bp,147bp)  .. (92bp,124bp);
  \draw (96bp,150bp) node[auto] {$\tau$};
  % Edge: q1 -> q2
  \draw [->] (56bp,177bp) .. controls (50bp,164bp) and (43bp,147bp)  .. (34bp,124bp);
  \draw (33bp,150bp) node[auto] {$\tau$};
  % Edge: q0 -> q1
  \draw [->] (63bp,264bp) .. controls (63bp,252bp) and (63bp,236bp)  .. (63bp,212bp);
  \draw (74bp,238bp) node[auto] {$a$};
  % Edge: q2 -> q4
  \draw [->] (35bp,89bp) .. controls (41bp,76bp) and (48bp,59bp)  .. (59bp,35bp);
  \draw (33bp,62bp) node[auto] {$\overline{b}$};
  % Edge: q3 -> q4
  \draw [->] (93bp,88bp) .. controls (88bp,76bp) and (82bp,59bp)  .. (73bp,36bp);
  \draw (95bp,62bp) node[auto] {$\overline{c}$};
  % Node: q0
\begin{scope}
  \draw [state] (63bp,282bp) ellipse (27bp and 18bp);
  \draw (63bp,282bp) node {$q_{0}$};
\end{scope}
  % Node: q1
\begin{scope}
  \draw [state] (63bp,194bp) ellipse (27bp and 18bp);
  \draw (63bp,194bp) node {$q_{1}$};
\end{scope}
  % Node: q4
\begin{scope}
  \draw [state] (67bp,18bp) ellipse (27bp and 18bp);
  \draw (67bp,18bp) node {$q_{4}$};
\end{scope}
  % Node: q2
\begin{scope}
  \draw [state] (27bp,106bp) ellipse (27bp and 18bp);
  \draw (27bp,106bp) node {$q_{2}$};
\end{scope}
  % Node: q3
\begin{scope}
  \draw [state] (99bp,106bp) ellipse (27bp and 18bp);
  \draw (99bp,106bp) node {$q_{3}$};
\end{scope}
%
\end{tikzpicture}
% End of code

%
\end{document}
%


